Friction stir welding method and structure body formed

Abstract

This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

1. A structure body comprising:
 a first member having a first plate, a second plate which is substantially parallel to the first plate, and a third plate for connecting said first plate and said second plate, said third plate being substantially perpendicular to the first and second plates, and the third plate having one recessed portion in one corner portion of one end portion thereof, and another recessed portion in another corner portion of another end portion thereof, and 
 a second member having a first plate and a second plate which is substantially parallel to the first plate of the second member, an end portion of the first plate of the second member being positioned in said one recessed portion so as to overlap said third plate with said end portion of the first plate of the second member, and an end portion of the second plate of the second member being positioned in said another recessed portion so as to overlap said third plate with said end portion of the second plate of the second member, and wherein the first plate of the first member and the first plate of the second member are on a same plane, and the second plate of the first member and the second plate of the second member are on a same plane, 
 with a first friction stir weld between said first plate of the first member and the first plate of the second member, at the end portion of the second member in said one recessed portion, and 
 with a second friction stir weld between said second plate of said first member and said second plate of said second member in said another recessed portion, 
 the structure body being formed by: 
 carrying out a first friction stir welding to the end portion of the first plate of the second member overlapping said third plate of the first member in the one recessed portion of the first member, 
 carrying out a second friction stir weld to the end portion of the second plate of the second member overlapping said third plate of the first member in the another recessed portion of the first member, 
 the first and second friction stir weldings being carried out from a side of an outer face of one side of said second member and a side of another outer face thereof, respectively, 
 the first friction stir welding being carried out between the first plate of the first member and the first plate of the second member at an extension line of a center of a width of a first bead of a first friction stir welding portion formed at the end portion of the first plate of the second member overlapping the third plate of the first member, and 
 the second friction stir welding being carried out between the second plate of the first member and the second plate of the second member at an extension line of a center of a width of a second bead of a second friction stir welding portion formed at the end portion of the second plate of the second member overlapping the third plate of the first member. 
 
     
     
       2. A structure body according to  claim 1 , wherein each of said first and second friction stir welds is a welding of an abutted portion between said first member and said second member. 
     
     
       3. A structure body according to  claim 2 , wherein:
 said first and second friction stir weldings respectively are carried out to a depth below said one and another recessed portions. 
 
     
     
       4. A structure body according to  claim 1 , having a remnant of said one recessed portion and said another recessed portion respectively at said first friction stir weld and at said second friction stir weld. 
     
     
       5. A structure body according to  claim 1 , wherein a center line of each of the first and second friction stir welds is positioned at an extension of a center of a width of the third plate. 
     
     
       6. A structure body according to  claim 1 , wherein said first plate of the first member is separated from the first plate of the second member only by said first friction stir weld, and wherein said second plate of said first member is separated from said second plate of said second member only by said second friction stir weld. 
     
     
       7. A method of forming a structure body, comprising the steps of:
 providing a first member having a first plate, a second plate which is substantially in parallel to said first plate, and a third plate for connecting said first plate and said second plate, said third plate being substantially perpendicular to said first plate and being substantially perpendicular to said second plate, said third plate having one recessed portion in one corner portion of one end portion thereof, and said third plate having another recessed portion in another corner portion of another end portion thereof, 
 providing a second member having a first plate and a second plate which is substantially in parallel to said first plate thereof, 
 a first arranging of said first plate of said first member and said first plate of said second member to be co-planar with each other, 
 a second arranging of said second plate of said first member and said second plate of said second member to be co-planar with each other, 
 a first overlapping of said one recessed portion of said third plate of said first member and said first plate of said second member, to form a first overlapped portion, 
 a second overlapping of said another recessed portion of said third plate of said first member and said second plate of said second member, to form a second overlapped portion, 
 a first abutting of said first plate of said first member with said first plate of said second member, to form a first abutted portion, 
 a second abutting of said second plate of said first member with said second plate of said second member, to form a second abutted portion, 
 carrying out a first friction stir welding to said first overlapped portion of said first plate of said first member and said first plate of said second member at said first abutted portion, 
 carrying out a second friction stir welding to said second overlapped portion of said second plate of said first member and said second plate of said second member at said second abutted portion, 
 said first friction stir welding being carried out from a side of an outer face of a side of said first plate of said first member and from a side of an outer face of a side of said first plate of said second member, 
 said second friction stir welding being carried out from a side of an outer face of a side of said second plate of said first member and a side of an outer face of a side of said second plate of said second member, 
 said first friction stir welding being carried out between said first plate of said first member and said first plate of said second member at an extension line of a center of a width of one bead of a first friction stir welding portion formed on said first overlapped portion formed by said first plate of said first member and said first plate of said second member, and 
 said second friction stir welding being carried out between said second plate of said first member and said second plate of said second member at an extension line of a center of a width of another bead of a second friction stir welding portion formed on said second overlapped portion formed by said second plate of said first member and said second plate of said second member. 
 
     
     
       8. A method of forming a structure body according to  claim 7 , wherein:
 said first friction stir welding is a welding of said first abutted portion between one end portion of said first plate of said first member and one end portion of said first plate of said second member, and 
 said second friction stir welding is a welding of said second abutted portion between one end portion of said second plate of said first member and one end portion of said second plate of said second member. 
 
     
     
       9. A method of forming a structure body according to  claim 8 , wherein:
 said first friction stir welding is carried out to a depth below said one recessed portion of said third plate, and 
 said second friction stir welding is carried out to a depth below said another recessed portion of said third plate.